The war saw the improvement and extensive use of various technologies prototyped in the Human-Covenant War, such as nuclear shaped-charge missiles, anti-plasma countermissiles, fragmentation warheads, and the first arsenal ships, all of which were instrumental in reducing the UNSC's vast numerical and technological disadvantage at the start of the war.

It remains a topic of considerable debate among historians as to whether the War of Vengeance can be considered to be a separate war or simply another period in the far more destructive First Great War. However, the Official Histories of the UNSC Army, Air Force, Marine Corps and Navy (J.R. Michaels, Luna Publishers, 2563, 2564, and 2566 respectively) consider it to be a separate conflict, and so that reckoning is used in this article to avoid confusion.

Contents

History

Beginnings

The War of Vengeance obviously has its roots during the First Great War. During the Battle of Earth in 2552, the vast majority of the vessels brought by the Prophet of Truth to the Sol System went through the Portal to Installation 00, and were destroyed by the pursuing Sangheili fleet. However, a small number of ships were able to escape into slipspace, one of which was pursued by a UNSC Prowler to a Jiralhanae-occupied Covenant colony known as Unmoving Virtue. The Prowler was able to gather a large amount of intelligence on the colony and its defences before returning to UNSC space. However, the intelligence was shelved by the UNSC, who preferred to focus on reconstruction rather than taking the war to the Covenant, who in any case, appeared to be a less important threat than a potential second Insurrection, given that they were ripping themselves apart in a civil war created by the death of the Prophet of Truth and numerous Jiralhanae Alpha Chieftans.

It quickly became clear to the UNSC that previous assessments of their casualties had been over-pessimistic: Out of the original eight hundred UNSC colonies, less than seventy had actually been found and glassed by the Covenant, the majority of them lightly-populated outposts, harbours of Insurrectionists that the UNSC had felt it could stand losing, and agriculture and industrial worlds. Even the majority of the colonies that the UNSC had evacuated or abandoned for fear of Covenant invasion were still habitable. However, this loss of productive worlds set back UNSC farming and industrial production significantly, and rationing and on some colonies, a one-child policy, had to be introduced on surviving planets to prevent food shortages. Furthermore, the Covenant had also succeeded in locating and attacking five of the UNSC's seventeen most heavily populated and oldest Inner Colony worlds (Earth, Reach, and Jericho VII among them). All of these worlds had populations going into the several billions, and these attacks resulted in the vast majority of the civilian population being killed. The population of Earth was reduced to a mere 200 million, and the attacks on these planets, combined with the military and civilian death tolls from the other colonies, brought the total death toll up to a staggering 23 billion - a tenth of the pre-war Human population. However, the UNSC still had a vast population to draw on for conscription and rebuilding. Re-establishing glassed colonies, relocating refugees and the rebuilding of the UNSCDF as an effective military force in the face of the Covenant were the UNSC's top priorities. Advances in missile, shielding, and DEW technology were rapidly applied to warships for the conflict that the UNSC was certain to come around when the Covenant managed to re-organise itself.

By 2555, the warring Covenant factions had mostly been united under the New Covenant, led by the Prophet of Objection, the Blood Covenant, under Chieftan Hephaestus, and numerous other smaller, but no less dangerous states such as the Kig-Yar Privateer Alliance. The New Covenant, however, was not yet prepared to continue the war with the UNSC and the Sangheili, and it is indeed possible that Objection had lost the stomach for another costly war. In contrast, the Blood Covenant was rearming at full pace and made no secret of its aims to destroy humanity, the Sangheili, and the San'Shyuum, whom they viewed as deceivers responsible for their ill-fortune during the First Great War, and decisively ended negotions with the New Covenant over a potential military alliance by sending the two ambassadors home in pieces.

With their shipping being constantly harrassed by Kig-Yar pirate vessels, and the Blood Covenant rapidly approaching the capacity to overwhelm them, the UNSC recovered the intelligence gathered at Unmoving Virtue, and together with the Sangheili, composed a plan for a strike against the Blood Covenant that would cripple their military capability, and act as a deterrent against further aggression. At the pressing of his senior military advisors and cabinet secretaries, as well as ArbiterThel 'Vadam of the Sangheili Armed Forces, UEG Secretary-General Pierre Plantard reluctantly made the unpopular move of committing the UNSC to an alliance with the Sangheili, and authorised a joint strike on Unmoving Virtue.

The Blood Covenant Campaign

First strike (December 2555)

The attack on Unmoving Virtue was conducted with the cooperation of the Sangheili Armed ForcesSecond Fleet of Enlightened Benevolence, and the UNSC 30th Fleet. The battle was a significant victory for both participants, and saw the deployment of numerous new technologies. In this regard, it served as a combat test for UNSC prototypes, proving their reliability and effectiveness in the field, and also functioned as a psychological deterrent against further Covenant aggression. For the Sangheili, it saw the liberation of thousands of captured Sangheili slaves from the shipyards, the destruction of three significant Jiralhanae fleets, and denied the Blood Covenant control of a strategically important naval shipyard.

Island Hopping (2556-2560)

The attack also proved to be a double-edged sword for the UNSC/Sangheili alliance, however: Jiralhanae politics being what they are, the leadership annihilated at Unmoving Virtue were quickly replaced, and the other worlds put on immediate alert. Another attack of the same scale would not be possible again for many years, until the Blood Covenant fleet had been left battered and disparate after years of swift, aggressive and devastating raids against the most significant nodal points, leaving worlds dependent upon them to "wither on the vine", reminiscent of the "Island Hopping" campaign envisaged by World War II Admirals Nimitz and Halsey.

Pious Ascension (February 2556)

After the defeat at Unmoving Virtue, the Blood Covenant moved their capital to Pious Ascension. However, given the planet's position as a key shipyard, a large population centre, and a major stop-off point and re-fuelling base for convoys heading for four other smaller colonies, it was an obvious target for the Island Hopping campaign, something that the Blood Covenant leadership apparently failed to appreciate.

The NOVA Bomb detonation at the Battle of Pious Ascension. It can be easily seen that the explosion has stripped the soil away from the ground and mountains and has melted the rock. In the top right hand corner, Pious Ascension's moon is in the process of shattering.

The force defending Pious Ascension was larger than the alliance was prepared to comfortably deal with, however, and so they planted disinformation to convince the Blood Covenant that an attack was to take place at the less well-defended but equally important world of Eternal Fealty. The Office of Naval Intelligence made use of an easy-to-break code to transmit the information between fleet formations, and even constructed a faux attack fleet that seemed to be poised to assault Eternal Fealty. Blood Covenant cryptanalysists and intelligence officers were convinced that the attack on Eternal Fealty would come at any time, and so Blood Covenant Naval Command made the decision to detach three dozen ships from the Pious Ascension fleet to reinforce Eternal Fealty, giving the allies the opening they needed.

An allied force of sixty-four ships arrived at Pious Ascension on February 2, 2556 and engaged the far larger but technologically inferior Blood Covenant fleet, dealing them heavy damage but taking enough losses in return to make a pyrrhic victory appear likely. However, the entire attack was a feint to draw the Blood Covenant's attention away from the real threat: Since Pious Ascension's garrison was too large to overwhelm with a ground assault, and the planet was too important to the Blood Covenant war effort to even allow them the possibility of recapturing it, the decision had been taken to utterly destroy the planet. An ONI Prowler launched a NOVA Bomb at the planet and utterly destroyed it, with the entire Blood Covenant fleet getting destroyed in the blast wave. Blood Covenant supply lines were tripled in length, and four Blood Covenant colonies were starved, surrendering three months after the battle. The Blood Covenant leadership, however, once again escaped, this time to Expansive Judgement, where they would remain until the end of the campaign.

Eternal Fealty (June 2556)

Emboldened by their two crushing victories, the alliance was prepared to carry out their threat to attack Eternal Fealty. The Blood Covenant was forced to commit more ships to convoy escort duty, as the UNSC's campaign of Unrestricted Prowler Warfare (see below) became more and more agressive and harmful to their ability to supply their dependent colonies. As a result, ships were stripped out Eternal Fealty's defence fleet in order to fill the gaps left by losses to Prowlers. Seeing that the Prowler campaign was doing the Blood Covenant damage in areas that they hadn't foreseen, AdmiralCarolyn Webster, Commander, UNSC Prowler Corps, ordered the campaign to be stepped up, to Supreme Commander Fleet Admiral Terrence Hood's enthusiastic approval. Eventually, Eternal Fealty's defence fleet had been reduced by half following losses on convoy duty. The allies came to the conclusion that the time to attack had come, and on June 18, 2556, a joint UNSC-Sangheili force entered the system.

Despite numerical parity, the demoralised Blood Covenant fleet was quickly dealt with by the allies, and the six-day ground campaign ended with very few (comparatively) allied losses. In the process, the men of the UNSC Army's 3rd Scottish Infantry Regiment captured a data centre in the planet's capital. After analysing the data, the UNSC learnt that the Blood Covenant was fighting a two-front war, one against them, and another against the New Covenant, and was slowly being pushed back on both fronts. What should have been good news was tempered by the fear that once the New Covenant had dealt with its secessionists, it would turn on the alliance. Fortunately, this proved not to be the case.

Determined Resolve (May-August 2557)

In the weeks and months after Operation Hammer (see below), the alliance fought to regain the iniative and offensive momentum from the Blood Covenant. In mid-May 2558, the allies captured the strategic Blood Covenant systems of Determined Resolve, Silent Reverence, and Worshipful Submission, which had been starved into surrender by the Prowler campaign. In the process, a salient - a huge bulge in the front lines - appeared. The Blood Covenant Naval Command saw this as tremendous opportunity to build on their success from Operation Hammer and encircle and destroy or capture the equivalent of three fleets and ten army groups.

Planned by Fleet Master Arboreus, the rising star of the Blood Covenant Navy, the attack, code-named Operation Citadel, was a double-headed encirclement movement that was first aimed at securing Silent Reverence and Worshipful Submission to the "coreward" and "rimward" of Determined Resolve. The massively-outnumbered UNSC and Sangheili pickets in the system were easily overrun by the tremendous Blood Covenant fleets, although the Sangheili were able to do some damage to them simply by fighting to the death. Despite these victories, the depth of planning, and the size of his forces, Arboreus remained unsure of the attack, complaining in a letter to his mate: "Whenever I think of this attack, my stomach turns over. A brilliant man would find a way not to fight a war."

His words were almost prophetic: Knowing the weakness of their position, the UNSC and Sangheili forces at Determined Resolve had built up deep webs of fortifications, both in space and on the surface in a defence plan code-named Operation: KURSK, inspired by those used in Operation: HOT GATES six years previously, and they were equipped with the new Glorious-class Carriers that had caused the Blood Covenant Navy so much grief at Alpha Centauri earlier in the year. Despite their supply lines being dramatically extended after the capture of Silent Reverence and Worshipful Submission, the UNSC Second,Sixteenth, and Thirtieth Fleets held out and fought running battles with the Blood Covenant in the system for over three months before they were reinforced. On the ground, eleven million UNSC and Sangheili soldiers fought twenty million Jiralhanae for control of the planet. Fifteen thousand tanks and eleven thousand aircraft participated in the ground campaign. Finally, on the sixteenth of August, the Sangheili Fleet of Enlightened Benevolence arrived to reinforce the allied forces. Arboreus called off the attack and withdrew his forces, and avoided execution on his return to Expansive Judgement by managing to foiste the blame for failure on "junior Fleet Masters and their incompetent execution of war plans." Fortunately for him, these "junior Fleet Masters" were in no position to defend themselves, having been killed during the battle. He did it out of a sense of preservation, knowing that with this defeat, the Blood Covenant would need him more than ever in the coming years. The Blood Covenant leadership recognised this as well, but knew that they could not be seen as weak by not punishing a defeated Admiral. Furthermore, Arboreus was a capable, popular officer and good leader, whom they saw as a person who could overthrow them. They chose to put Arboreus as far away from the capital as possible, and so bundled him and his fleet off to the marginally important Undefeated Glory system until they really needed him. Arboreus didn't get a chance to come home, however, before he was killed at the Battle of Undefeated Glory during Operation: FURY in 2560. The Battle of Determined Resolve is often seen by historians as an arbitrary point after which the Blood Covenant clearly began to lose the war.

The Thorn Wall (September-November 2558)

The UNSC/SAF attack on the Thorn Wall, code-named Operation: BAGRATION, was aimed at finally overturning the Blood Covenant's offensive momentum and forcing them back on to a defensive footing. After their rout at Determined Resolve, the Blood Covenant pulled back to a massively fortified line of planets known as the Thorn Wall, designed so that any besieged planet in the line would be able to hold out until reinforcemnts from the flanks or rear arrived. Furhermore, its sheer size meant that multiple attacks along the line would be impractical and unacceptably costly. Therefore, the alliance was forced to consider a new plan.

The eventual solution was based on that of deep operations, originally a land-based doctrine where corps-sized forces would strike deep into the enemy's rear to deprive his front line of support. Two enormous joint Sangheili-UNSC task forces were assembled in the months after the Battle of Determined Resolve, and in January 2558, set off on a course out off UNSC space, one heading coreward, the other rimward, on round-about routes that would take them around the Thorn Wall and through the poorly-defended coreward and rimward borders of the Blood Covenant, an operation that Blood Covenant Naval Command had never even considered the possibility of. Outnumbering the Blood Covenant defence fleet five-to-one, the two task forces arrived in the Ambient Wonder system, the most heavily-defended of all the rear support bases, and after a two-day battle, destroyed the fleet, orbital infrastructure, and ground-based garrisons and supply dumps. Not even taking the surrender of the survivors, the task forces continued, destroying supply bases in the Balst, Tapach, and Walresh systems, completely cutting out the rear of Combined Operations Group Centre (COG-M). In November, 2558, UNSC and SAF forces moved in on COG-M in three separate systems, destroying the starved and under-equipped force. With their centre compromised, Combined Operations Groups Coreward and Rimward withdrew from the Wall deep into the heart of Blood Covenant space, ceding dozens of vital shipbuilding and industrial systems to the alliance. At this point the alliance reasoned that it was now certain that the Blood Covenant would lose the war, the only question being how long it would take.

Cloistering Expectancy (December 2558)

Cloistering Expectancy is a small world, and was home to a not-insignificant Huragok colony with a population several thousand strong. Though the population was technically neutral, the planet was also on the edge of Blood Covenant territory. Having just regained the initiative from the Blood Covenant, in part through technical superiority, the alliance was not prepared to throw that away by allowing the Blood Covenant access to the finest engineers and technicians in the Galaxy. The Battle of Cloistering Expectancy was conceived as a pre-emptive strike on the world by the Sangheili to deny the Blood Covenant the services of the Huragok. It would also become one of the most controversial acts of the entire war.

Not wanting to antagonise the Huragok into switching sides to the Blood Covenant, the UNSC convinced the Sangheili to allow them to bring along the Huragok defector to the UNSC, Too Much Ballast, in the hope of convincing the colonists to join them without the need for coercion. Unfortunately, mission security was atrocious on the Sangheili's part, which resulted in the Blood Covenant leadership discovering the operation via the Brotherhood of Ruskt. Negotiations with the Huragok via video-link appeared to be going well at first, despite the colonists forbidding Too Much Ballast to land on the planet's surface due to his "treachery", but an hour into the talks, a Blood Covenant fleet arrived in the system with the intention of claiming the colony through force. Outnumbered five-to-one, the small, mostly ceremonial delegation of Sangheili ships had no chance of defeating them, and so were forced to destroy the Huragok colony with a plasma torpedo bombardment. Not wanting to fight a useless battle, the Blood Covenant force withdrew and ceded the now-unnecessary system to the alliance. Unusually, the Sangheili apologised in the strongest possible terms to Too Much Ballast, who withdrew to his quarters for three weeks after the battle (ONI investigators later found that he had destroyed and rebuilt everything in the room twenty-two times). During this time, he communicated with other captive Huragok and organised two hundred of them in an independence movement. On New Year's Eve, 2558, this group stole into the Reyes-McLees Martian Shipyards, rapidly repaired a badly-damaged corvette in the course of an hour, and set a course out off UNSC space, never to be heard from again until 2566, when it was established that they had founded a new Huragok colony, Freedom For All, based on Marxist principles, which to the surprise of Human investigators, actually worked in practice as well as principle, in contrast to Human attempts at setting up a Communist state.

The concept of Unrestricted Prowler Warfare is fundamentally similar to that of 20th and 21st Century unrestricted submarine warfare: Use a stealthed craft, difficult to detect, to hunt down a fleet of enemy merchant ships and destroy them using extreme force. Controversially, in both cases, the attacked craft cannot surrender, allowing the Prowler or submarine to do the maximum possible damage. The objective was to destroy enough merchant ships to effectively starve the enemy into submission.

During the Blood Covenant Campaign, where UNSC Prowlers acted against Blood Covenant convoys, this part of the war was very reminiscent of German tactics in the Battle of the Atlantic in World War II or the latter part of World War I, with the use of massed groups of Prowlers, unhealthily dubbed "Wolf Packs", against convoys. The main steps in this tactic were as follows:

A number of Prowlers were dispersed across possible paths of a convoy. The campaign was made extraordinarily easier for the UNSC since they had broken the Blood Covenant's frankly laughable encryption codes for classified messages. Since departure and estimated arrival dates were known, the UNSC did not have to waste countless resources and thousands of hours of precious time constantly staking out routes.

A Prowler sighting the convoys would signal its course, speed and composition to the local Central Command.

The Prowler continued to shadow the convoy, reporting any changes.

Once the destination of the convoy was determined by putting the convoy's current travel time and slipspace velocity into the distance-time equation, the rest of the pack was ordered to close to the convoy's destination.

When the pack was formed, a field of HORNET Mines would be layed in the path of the convoy.

When the convoy reverted from slipspace, it flew straight into the path of the minefield. The surviving ships would be finished off with a barrage of fragmentation and nuclear-shaped charge missiles from the Wolf Pack.

Despite widespread controversy, the campaign was enthusiatically championed by AdmiralCarolyn Webster, Commander, UNSC Prowler Corps. However, many vocal public figures challenged the campaign as underhand, cowardly, and dirty. Even the Sangheili chose not to launch a similar campaign of their own, seeing such "sneak attacks" as cowardly and dishonourable, although they grudgingly admitted that it had results. As the UNSC's campaign of Unrestricted Prowler Warfare became more and more agressive and harmful to the Blood Covenant's ability to supply their dependent colonies, the Blood Covenant was forced to commit more ships to convoy escort duty. As a result, ships were stripped out of the defence fleets of important planets in order to fill the gaps left by losses to Prowlers. This allowed the alliance to destroy a disproportionate amount of ships to their own losses, which were far less than those they would have encountered in open battle with the Blood Covenant. Nearly 150 billion tonnes of shipping were lost to UNSC Prowlers over the course of the war. Over three dozen Blood Covenant colonies were starved into surrender without a fight by the Prowler campaign.

The Blood Covenant strikes back (March-May 2557)

By 2557, the Blood Covenant were in poor shape. Since they lacked the technical experience of the San'Shyuum, the Huragok, and even the Sangheili, they were finding it exceedingly difficult to repair badly-damaged ships, and the task of building an effective warship class of their own was almost beyond them. This terrible weakness was beginning to bite after the losses from Operation: MACARTHUR and the UNSC's Unrestricted Prowler Warfare campaign. The Blood Covenant needed to find a way to slow the alliance down in order to buy time to regroup and rebuild.

However, the alliance was in not much better a shape either. Though their technical expertise was decidedly superior to the Blood Covenant's, the Sangheili Armed Forces also lacked the knowledge to build their own ships from scratch, and given their sense of pride and honour, were not prepared to accept help from the UNSC to build new ship classes. A large number of Sangheili still considered Human technology to be "inferior" to their own, which was, after all, inherited from the Forerunners, despite the fact that this attitude had been proven false again and again. The Sangheili's best hope for new ships was a series of pre-built hulls in the Morhekan Shipyards around Ketesh, which they were refitting to current standards with the latest equipment. Blood Covenant intelligence, working through the Brotherhood of Ruskt, discovered the existence of these new ships and recognised their value for the weakening Blood Covenant war machine.

Planned by Fleet Masters Arboreus and Gargantum, Operation Hammer, as this new Blood Covenant offensive was known, was aimed at crippling the Sangheili and UNSC military-industrial complexes and bolstering the Blood Covenant Navy with a new fleet of warships stolen from the Morhekan Shipyards. Given the fact that the UNSC was beginning to have a greater role in space-based operations than the SAF, given their rapidly-growing ship numbers, most of the Blood Covenant's targets were UNSC shipyards or mining facilities, aimed at destroying the alliance's space superiority. A strike on Ketesh in overwhelming force was planned to destroy the defending Sangheili fleet and raid the shipyards for the new warships. The targets for the operation were the UNSC shipbuilding and mining systems of Sigma Octanus, Alpha Centauri, and 23 Librae, and the Sangheili worlds of Ketesh, and Thorak'tamin in the Devout Foreboding system. The strike at Devout Foreboding was aimed at capturing the technologically-advanced Forerunner ruins on the surface.

Sigma Octanus IV (March 2557)

Because of its position far from the front lines of the war, Sigma Octanus IV had been chosen by the UNSC as one of the sites for a new series of shipyards. In hindsight, this was a poor decision, given that the Blood Covenant was aware of the system's location, having already attacked it during the First Great War. Twenty Blood Covenant Vrathek-Class Cruisers jumped into the system and easily overwhelmed the defending UNSC Battlegroup, before dismantling the shipyards and destroying the fifty five half-built warships in their building cradles. In an unusual display of tactical innovation, Fleet Master Arboreus, the Blood Covenant commander, ordered his ships to use their Energy Projectors to destroy the UNSC ships rather than closing and utilising more traditional plasma torpedoes, the result being that the UNSC force could not block the energy projector beams with countermissiles or strike back, as the Blood Covenant force was out of range of their missiles. Only one Destroyer managed to escape to the nearest allied system, but arrived too late; an SAF convoy carrying raw materials and troops had already set course to the Sigma Octanus system and was captured outright on its arrival, resulting in the enslavement of twenty thousand Sangheili servicemen. Managing to capture an entire Sangheili resupply convoy, destroy a vital human shipyard, and humiliate the UNSC/SAF forces, Arboreus was justifiably satisfied with his victory, jumping his fleet away without glassing the planet - later accounts would insist that he did it out of a personal sense of honour, seeing none to be gained by glassing a defeated planet. Others point out that Blood Covenant plasma production has never been the most efficient, and that it is more than likely that Arboreus simply had no desire to waste such a valuable commodity.

23 Librae (March 2557)

At the same time, twelve Blood Covenant warships arrived in the 23 Librae System with the objective of destroying the reestablished UNSC mining facilities in Hesiod's ring system and the system's main belt. Only four of the Blood Covenant vessels were capital ships, however; the remaining eight were antimatter mine layers. As the UNSC picket advanced towards the numerically inferior Blood Covenant force, the minelayers launched hundreds of stealthed antimatter mines into the main belt and Hesiod's rings. Six of the largest mining asteroids were shattered into fragments by the explosions, and the resulting clouds of debris collided with smaller asteroids, smashing the mining facilities and setting back mineral production in the system for over two years. The Blood Covenant fleet escaped the system before the UNSC force could fire a single shot at them.

Devout Foreboding (late March-early May 2557)

The attack on Thorak'tamin in the Devout Foreboding system was aimed at securing the technologically-advanced Forerunner Venartheman ruins on the surface in an attempt to improve the Blood Covenant's technological capabilities in the face of rapidly improving UNSC warship technology. Had the attack actually been successful, however, it is unlikely that the Blood Covenant would have been able to make anything of them, given the relative crudity of their techological base and the increasingly partisan actions of the Huragok. Seventy five warships entered the system, making a pinpoint slipspace jump right in front of the Sangheili picket, which was outnumbered five-to-one. Even with the enormous power drain created by pinpoint jumps, the Blood Covenant fleet was able to get its weapons back online before the surprised Sangheili could even get their shields up. Fifteen ships were totally wiped out in less than ten minutes. On the surface, however, things did not go as well for the Blood Covenant. The ground force took anti-air fire as it went down and had to land fifty kilometres south of the ruins, in the middle of one of the harshest deserts in the Orion Arm. Unprepared for these sweltering conditions, the force met with staunch resistance from the SAF garrison, who had great experience of fighting in desert conditions, and even from the prisoners who had been sent their as a test of redemption.

Things began to go from bad to worse for the Blood Covenant, when they realised that they ruins they so desperately sought were not even on Thorak'tamin - what they had thought to be a Forerunner weapons cache turned out to be an ancient Covenant research base, set up to observe the ruins in the gas giant the moon orbited. Humiliated by this revelation, and intimidated by the arrival of the Fleet of Enlightened Benevolence to reinforce the garrison, Fleet Master Gargantum panicked and ordered his forces off the surface, indiscriminantly glassing both his own and SAF troops in a clumsy attempt to cover their retreat. Unwilling to leave the research base for the Sangheili, he also attempted to destroy it with his energy projectors, broadcasting his intent to destroy "Forerunner relics" to the Sangheili - unfamiliar with the system, and hesitant to provoke such an action, the fleet was forced to hold off as the Blood Covenant made their retreat. As local Sangheili forces informed them of the facts, however, the fleet moved in, furiously devastating every ship present, refusing to accept even the possibility of a surrender. Out of the entire fleet, only Gargantum and his ship escaped, and upon his return to Expansive Judgement, he was executed for his failure and cowardice. Unusually, his cowardice induced the Blood Covenant to send a single diplomat to apologise to the Sangheili for Gargantum's incompetence and dishonourable actions - the diplomat would never be heard from again, and rumours hold that Arbiter Thel 'Vadam had him executed without ever hearing the apology.

Alpha Centauri (May 2557)

The only unquestioned Blood Covenant defeat occured in the Alpha Centauri System. Between the Blood Covenant's reconnaissance of the system and the attack, twelve of the UNSC's new Glorious-class Carriers had been moved to the Alpha Centauri shipyards for final fit-outs and training exercises. The Blood Covenant's objective was to destroy the UNSC's shipyards in the system. If they had succeeded, this would have been a major blow to the alliance war effort, given the dominant role the UNSC was taking in space combat. One hundred and twenty five Blood Covenant ships arrived in the system and engaged the ninety-ship strong UNSC defence fleet. Sixty squadrons of the new and incredibly powerful C800 Blackburn Claymore Space Superiority Fighters were launched from the carriers and supported the fleet in the action, to the Blood Covenant commander's total surprise. Equipped with missiles and Electronic Warfare equipment from Project EXCALIBUR, the fighters and carriers assisted in the decimation of the Blood Covenant fleet and Shipmaster Magnus was forced to order a retreat after Fleet Master Gnaeus flagship was destroyed early on in the action. He was not executed for this action due to the fact that he was able to warn Blood Covenant Naval Command of the existence of the new fighters, a threat that they would face once again at the Battle of Determined Resolve later in the year.

Ketesh (May 2557)

At Ketesh, the alliance suffered perhaps its greatest blow in terms of fighting capability. The Blood Covenant sent three hundred ships, its largest offensive fleet up until then in the war, into the Devout Induction system in an attempt to capture the Morhekan Orbital Shipyards and the ships in them for their war effort. Though still outnumbered by the defending fleet, the Blood Covenant jumped out of slipspace as close to Ketesh as possible and managed to force their way through to the shipyards and boarded them, holding the workers hostage. The Sangheili force was unwilling to fire upon the Blood Covenant fleet from the range they were at, lest they hit the shipyards or the heavily populated surface of Ketesh. However, the defending forces in the shipyards repelled all attempts at gaining control, and even in the sections that they captured, the Sangheili workers refused even under threat of torture to finish the ships for the Blood Covenant. When they attempted to force the Huragok to complete the ships, they found that the Sangheili had already killed all of them as a precaution. Frustrated, the Blood Covenant forces set antimatter charges throughout the shipyard, destroying the facility rather than allow the Sangheili to continue to use it in their war against the Blood Covenant. However, with their only bargaining chip foolishly cast aside, the understandably furious Sangheili Shipmasters ordered the fleet to close on the Blood Covenant force and wiped them out to the last ship.

The operation proved to be a tactical success for the Blood Covenant, and achieved one of its objectives of slowing the alliance down. It also gave them some warning of the new Claymore fighters and Glorious-class Carriers that the UNSC would later deploy at Determined Resolve and Ambient Wonder. The impact on UNSC morale was also measurable; the number of UNSC civilians who wished to make peace with the Blood Covenant increased after the Battle of Alpha Centauri, understandable considering how close the Blood Covenant had come to Earth. However, the operation, and the atrocities it involved, made the SAF and UNSCDF only more eager to continue the war and attempt to regain the initiative.

Phoney war (2559)

By 2559, the war appeared to have ground to a halt, at least in the eyes of the UNSC public. There were none of the massive battles between opposing fleets and armies dominating the news networks, and while the campaign of Unrestricted Prowler Warfare continued, it was almost completely unappreciated by the public. As such, many were calling for the official cessation of hostilities, especially since the emergency wartime tax measures instituted by the Plantard Administration were beginning to hurt less-affluent families, and the public were quickly becoming bored of hundreds of petty and not-so-petty inconveniences such as increased fuel tax and inflated food prices.

For the UNSCDF and SAF however, the war was far from over. The Kig-Yar Privateer Alliance was preying on UNSC and Sangheili civilian shipping, necessitating a build-up in numbers of light warships for convoy escort. Furthermore, the allied Combined Chiefs of Staff were convinced that there could never be peace with the Blood Covenant unless their current government was removed and their war-fighting capability completely destroyed, an opinion which allied civilian leaders shared. The Prowler campaign was stepped up and the allied fleets and armies were rebuilt and re-equipped in preparation for a new offensive. However, as his position in opinion polls continued to slip in favour of Jerome Smithson, leader of the UNSC Liberal Party, Pierre Plantard knew that he would have to find some justification in continuing the war against an enemy that to the public appeared beaten. Ultimately, it was the Blood Covenant that gave it to him.

Operation Tartarus (2560)

By 2560, the Blood Covenant was in such dire straits that they were willing to consider any option that might gain them the initiative, however briefly. With the New Covenant attacking them from one side, and the UNSC and Sangheili from the other, the Blood Covenant leadership was desperate to relieve the pressure from the UNSC/Sangheili alliance, so that more resources could be concentrated against the immeasurably more powerful New Covenant. With the loss of dozens of critical shipbuilding facilities, in addition to hundreds of vessels, the Blood Covenant Navy was unable to launch a repeat of Operation Hammer lest they uncover a vital system and do themselves even more damage. Therefore, the only option they could think of was a political operation, specifically, the assassination of a key allied leader to throw the alliance into turmoil, slowing them down or even halting them completely. Given that they had an - admittedly shaky - understanding of Sangheili politics, the Blood Covenant chose not to attempt an assassination of significant Sangheili, knowing that someone just as capable or better would take the dead leader's place under the Sangheili's meritocratic principles, and so they chose to focus their efforts on removing the UNSC from the war. Jiralhanae understanding of human political structures and motivations has been understandably poor, given how far removed their own society is from the democratic institution that has served humanity's interstellar government needs. Their own society is a patriarchal kritocratic hierarchy, where males achieve power by defeating their superiors, moving up the chain of command as available posts become available. As such, it is not difficult to see how they concieved of Operation Tartarus.

To the Jiralhanae, the answer to the UNSC's continued involvement was simple - cut off the head of the snake, and the body dies. Fleet Admiral Lord Terrence Hood, 23rd Viscount Hood, effectively the benevolent military dictator of the UNSC during the Human-Covenant War, was seen as the most strategic candidate for removal. His influence upon the military was not inconsiderable, and without him, they believed, the UNSC would grind to a halt as rivals fought to fill his place, and the general populace would lose the will to fight. It was also meant to demonstrate to humanity that even their heroes were not invulnerable. While the Sangheili had cultivated a reliable spy network within the Brotherhood of Ruskt, with which the Blood Covenant had cool relations with, this would prove to be a double edged sword for them - the same network was used to gain information on Hoods projected locations and timetable, and an assassination fleet was rapidly assembled.

What occurred, however, was certainly not the well-oiled precision of comparable UNSC and Sangheili operations. During a military inspection of the politically sensitive Middangeard ruins, the Blood Covenant appeared in orbit, engaging the limited colonial defence forces in orbit, blowing past the two orbital defence platforms and landing thousands of troops on the planet. In the ensuing ground combat, Hoods location was overrun, and the Admiral was killed by Jiralhanae forces before rescue teams could arrive. As response groups arrived to combat the enemy attack, a Sangheili delegation arrived in-system. Originally scheduled to take part in a ceremonial dedication on the colony, the fleet instead became part of a pincer formation, trapping the Blood Covenant fleet. While UNSC ships closed and engaged the main force, the Sangheili picked off stragglers and other ships attempting to flee. By the end of the space battle, not a single ship had escaped the slaughter. The ground battle was less smooth, and only the orbital support provided by the UNSC Navy and SAF Fleet allowed the local forces to retake the capital.

Technically, the operation was a decided success. It saw the death of a prominent military figure, as well as demonstrating that the Blood Covenant still had the capability to attack UNSC colonies, even while fighting a two-front war against the New Covenant and Sangheili Armed Forces. The response to it was decidedly different to that expected by the Blood Covenant. Rather than demoralising the UNSC, the attack served to infuriate humanity. Where before protests had been staged calling for the immediate withdrawal of human personnel and materiel from a war percieved by many as irrelevant, now public opinion swung back in the UNSC's favour, producing a public outcry and outrage. The UNSC would immediately step up its operations, increasing funding for special warfare projects, and mobilising the entire armed forces for the first time since the Human-Covenant War in the name of colonial security.

Exultant Piety

The Battle of Exultant Piety took place approximately three months before the rest of Operation: FURY. Given the vast number of Blood Covenant warships in the system, UNSC High Command reasoned that a vast number of missiles would be needed to defeat them, and so the first of the UNSC's new arsenal ships, Invincible and Retribution were rapidly completed, after having their construction suspended indefinitely throughout the Human-Covenant War, and after promising trials and shakedown cruises, the two were sent into the Exultant Piety system.

The battle was Invincible and Retribution's baptism by fire, and they performed superbly. Protected by a screen of frigates and destroyers, but still outnumbered six to one, both ships utterly destroyed a combined Jiralhanae and Kig-yar fleet in orbit of the planet with no casualties. Using the new Multi-Stage Missiles, the UNSC fleet launched its first - impossibly large, in the Blood Covenant's eyes - salvo from approximately triple the distance from the Blood Covenant fleet as it would have done had it being carrying conventional missiles. The original Blood Covenant tactic of trying to shoot down the EMP missile before it reached deployment range was rendered useless by the fact that every missile now carried an EMP generator, and their point defence and anti-missile electronic countermeasures were useless in the face of new UNSC electronic warfare systems mounted in the missiles. Invincible suffered severe hull damage from Covenant plasma, but there were no crew deaths. The Blood Covenant fleet was totally wiped out, and the UNSC fleet proceeded to destroy Eternal Piety's orbital forts and shipyards, and precision THOR strikes destroyed ground-based, factories, military bases, and spaceports. A Sangheili occupation force moved in a week later.

The battle was a resounding success for the UNSC, and authorisation was given to continue Operation: FURY, and to continue the construction of dozens of new arsenal ships, which would ultimately prove to be the most decisive weapon in the alliance's arsenal for the rest of the war.

Undefeated Glory

Another nineteen half-built arsenal ships were rapidly completed in the three months between the Battle of Exultant Piety and the rest of the operation. Built around a solid core of twenty-one Invincible- and Retribution-class ships, the newly designated Task Force Fury was assembled at a point twelve light years from the Undefeated Glory system in June 2560. Led by AdmiralRichard Lash aboard UNSC Invincible, the task force consisting of one hundred and fifty two UNSC ships of the line leapt into the system, with a Sangheili ground force tagging along behind them. Blood Covenant defences in the system were considerably stronger than those at Exultant Piety, and the UNSC was slightly outnumbered, but the Blood Covenant commander, Fleet Master Arboreus, had quite literally no idea what was coming. After first detecting the arsenal ships, he believed them to be a force of Marathon-class Cruisers and Glorious-class Carriers, which the UNSC had deployed at Determined Resolve two years previously. Surprised that what he thought were carriers had not deployed their fighters, he took advantage of this apparent tactical incompetence and ordered his destroyer and frigate screen to advance in an attempt to break through the UNSC screen so that his capital ships would have a shot at the "carriers".

What followed was a complete disaster for the Blood Covenant. Their screen was completely destroyed before it could enter weapons range by massed MSM fire from the UNSC screen and Retribution-class Battlecruisers. With no screen boosting his missile defence, Arboreus ordered a retreat, not out of cowardice, but to warn the Blood Covenant of the new weapons at the alliance's disposal, and he was no longer concerned about his personal honour. His flagship, however, was completely destroyed by fire from UNSC Invincible and UNSC Furious. Three Covenant Frigates managed to make it out of range and tried to escape to the Safe Slipspace Entry Point, but then two Glorious-class carriers came out from behind a screen of Prowlers in front of them and they were utterly destroyed by ten squadrons worth of Claymore fighters.

The battle was an unqualified success for the UNSC. Casualties were taken during the follow-up ground offensive, but were fractions of the tremendous Blood Covenant losses. Blood Covenant infrastructure and shipyards in the system were repurposed by the Sangheili to rebuild their strapped fleet. Not a single Blood Covenant ship escaped the system to warn their High Command about the arsenal ships, but lax regulations on communications between Blood Covenant POWs and their families meant that reports reached the ears of the Blood Covenant Naval Command through personal letters, although the oftentimes exaggerated and fantastical descriptions of the arsenal ship's capabilities were routinely ignored.

Wondrous Enlightenment

Despite Wondrous Enlightenment's status as the Blood Covenant's sole remaining significant shipyard, Wondrous Enlightenment was so far from the front lines (on the other side of Expansive Judgement, relative to Earth) that the Jiralhanae fleet commander had ordered his forces to stand down with shields and engines deactivated in order to avoid wear on components. (understandable, given the Blood Covenant's slowly collapsing economic and industrial base) This worked against them spectacularly, however, when Task Force Fury arrived in the system.

Having dropped off ten squadrons of Blackburn Claymore fighters a light-day from the primary planet, these fighters slowly made their way in-system under stealth over the period of one week. Coming out of stealth at the absolute last moment, they fired a salvo of shipkiller missiles that destroyed the majority of the ships' engines and weapons systems, paralysing the ships in orbit. Moments later, the rest of Task Force Fury came out of Slipspace and destroyed them with a massive missile salvo. This change in tactics was decided upon as the alliance had no desire for any warships to escape and inform Blood Covenant Naval Command of the arsenal ships' effectiveness. Unfortunately, a squadron of Destroyers had been out on exercises at the time of the attack and managed to escape to Expansive Judgement with sensor records of the battle, giving Naval Command a chance to develop a defensive doctrine against the arsenal ships.

Glorious Fraternity

Despite their rapidly-collapsing position, the Blood Covenant still had some fight left in it. Examining the data from the Battle of Wondrous Enlightenment, Blood Covenant Naval Command correctly assumed that the Invincible- and Retribution-classes could not fire their missiles off-bore. After examining the allies' former deployment patterns, they reasoned that the most likely target was the Glorious Fraternity system, a significant food production base, and so assembled every available warship in the system. However, they also left a significant force in Slipspace, ready to jump out and hit the sterns of the arsenal ships when they presented their broadsides to the Blood Covenant fleet. UNSC FLEETCOM, which by this time, was becoming hubristic about Project EXCALIBUR's capabilities, only saw the huge numbers in the Glorious Fraternity system as more to destroy, despite a five-to-one numerical disadvantage and the warnings of the Sangheili.

Arriving in the system, Task Force Fury took position at maximum missile range and opened fire. Despite managing to destroy a significant number of ships, the Blood Covenant's defence plan had been based upon the only option available to them - a wave attack. The fleet charged the UNSC force at maximum acceleration and, despite losing hundreds of ships, managed to close to effective energy projector range and open fire. Simultaneously, the second force came out of Slipspace on the Task Force's left flank, concentrating their fire on five Retribution-class ships. Despite their heavy shielding, one Battlecruiser, UNSC Audacious, was taken out of action with the loss of her offensive missile armament. Admiral Lash ordered his Battleships to concentrate on the larger, forward force and the Battlecruisers to cover the Battleships' sterns and handle the flanking force. However, a large number of screening warships had already been lost and, despite attempts to protect her, Audacious was struck by another energy projector blast and was lost with all hands. Despite managing to force the Blood Covenant force into retreat, many more Retribution-class ships were heavily damaged and the majority had shot their magazines dry, revealing fundamental weaknesses in the Battlecruiser design that led many to question their effectiveness. Moving on to Glorious Fraternity, the bloodied fleet carried out its orders, and released a chemical defoliant into the atmosphere that destroyed all food crops, before bombarding significant military bases and withdrawing to leave the planet to starve. Today the act is considered by some to be a punitive war crime.

Expansive Judgement (2561)

After the annhiliation of Pious Ascension, the Blood Covenant's capital had been moved to Expansive Judgement. They believed that an attack on the planet would be impossible - the sheer number of ships and orbital defences rendered it practically immune to orbital assault, and the billion or so Jiralhanae population would render a ground campaign pointless. In any case, the Alliance had virtually no idea of the sheer scale of the defences, much less the planet's location.

However, during the anti-piracy Operation: CORSAIR, the Prowler UNSC One-Eyed Wanderer succeeded in attaching a telemetry probe to the Kig-Yay Privateer ship Heikekatohuia, which retreated to the Expansive Judgement system to refuel and repair. The probe gave the UNSC an unprecedented look at the planet's defences. Discovering a Kig-yar privateer base near a Blood Covenant hydrogen/deuterium/tritium refinery station in orbit over Gargarensis, a gas giant further out in the system than Expansive Judgement, shrouded by a field of debris, the UNSC formulated an operation designed to insert an attacking battlegroup with a pinpoint slipspace jump in order to destroy the refinery station, as well as a number of Kig-yar privateer colony asteroids. The refinery provided crucial gases for the Blood Covenant, especially weapons-grade and fuel-grade plasma - without it, the fleet would soon literally grind to a halt, becoming ineffective, leaving the colony vulnerable.

Unlike the massive battles that had dominated Operation: FURY, the operation was conceived as a pinpoint strike by a small force in preparation for a single larger assault. In spite of protests from the Sangheili, the UNSC was determined to give the Blood Covenant a chance to surrender without further bloodshed. The arsenal shipsInvincible and Retribution were the only two capital ships assigned to the battlegroup. Arriving in orbit of Gargarensis while a massive Sangheili fleet arrived on the other side of the system to draw away the Blood Covenant defence fleet, they destroyed the Kig-Yar colonies and mining outposts around the planet. As the Sangheili engaged the Blood Covenant fleet, a third fleet commanded by Fleet Master Erebus of the New Covenant, arrived in the system and demanded the surrender of both the Blood Covenant and the SAF. Fleet Master Zuro Dun 'Xoram instead directed Erebus' attention to the two arsenal ships making their way towards the three-fleet standoff. Opening fire from half a million kilometres outside the New Covenant's engagement range, they utterly destroyed the tattered Blood Covenant fleet. Witnessing the firepower of the arsenal ships, mistakenly assuming that this was standard for modern UNSC warships, Erebus instead offered a temporary truce - in exchange for staying out of the New Covenant's attack on the Blood Covenant, he would permit the UNSC and Sangheili to retreat through slipspace. 'Xoram offered a counter offer - in exchange for burning the Blood Covenant world to a glowing cinder, he would bring the offer of a truce to the Arbiter. Not knowing the other sides' strength of numbers or firepower, neither the New Covenant nor Sangheili were willing to declare war upon each other, especially when the Blood Covenant was still to be dealt with. Erebus agreed, and the UNSC and Sangheili departed.

The effectiveness of various new UNSC space weapons technologies in the battle led to the New Covenant and the alliance signing the Unmoving Virtue Non-Aggression Pact, which kept the New Covenant out of the war, at least against the UNSC-SAF alliance. The New Covenant would wage its own campaigns of conquest and absorbtion, but would remain outside of UNSC-SAF combat theatres, leaving them to their own devices. The pact would remain in force until 2565, when the New Covenant enacted Operation Twilight of the Gods against the UNSC.

The Interminable Reprisal Campaign (2560-2562)

The fall of the Covenant saw the rise of the Kig-Yar Privateer Alliance - finally free from the Prophet's decrees that they be forbidden to use slipspace-capable ships, the sudden and dramatic appearance of Kig-yar piracy as a major threat to the shipping of all factions caused significant alarm amongst FLEETCOM. Already fighting wars against the Blood Covenant and waging a cold war of intelligence against the New Covenant, the UNSC was unwilling to let this threat continue, especially against its poorly defended reclaimed colonies.

Operation: CORSAIR (2560)

Operation: CORSAIR was intended as the beginning of an infiltration operation by the UNSC, locating a major Kig-yar privateer base, hoping that its destruction by a UNSC battlegroup, including a number of the new Arsenal Ships fielded by Project EXCALIBUR, would unsettle the balance of power in the Privateer Alliance, and send a message to the Kig-yar that preying on human colonies would not be tolerated. To this end, a trap was set in orbit over Megiddo, a site of significant Kig-yar raids - a "crippled" freighter was attached with a slipspace beacon, technology borrowed from the Sangheili Armed Forces. The Operation commanders expected that the Kig-yar, seeing only a salvage opportunity, would tow the freighter back to their base of operations through slipspace - a special warfare team would then infiltrate their base and place a the beacon aboard and send the UNSC a signal pinpointing its location, allowing the battlegroup to move in and wipe the base out.

Spartan-II Indigo Team, already in the system to assassinate a secessionist cult leader, were redeployed to place the beacon aboard the requisitioned freighter Messor in the cargo hold. An archer missile fired by the Prowler One-Eyed Wanderer crippled its thruster and slipspace pod, leaving it immobile, a perfect target for the Kig-Yar - and, as predicted, a Kig-yar ship soon arrived to investigate. Unfortunately, rather than tow the ship through slipspace immediately, the ship deployed boarding craft to investigate. Faced with the prospect of fighting in a zero-gravity environment against a company of Kig-yar mercenaries, Indigo Team instead performed an EVA infiltration - rather than wait to be towed to the base, they boarded the Kig-yar ship itself from there. Finding little of worth, and suspicious of the damage inflicted by a human weapon, the Kig-yar destroyed the freighter with their pulse laser weapons and jumped back to their base.

A near failure, Indigo Team's quick actions would have dramatic consequences. Rather than a mere Kig-Yar Privateer Alliance base, the ship had jumped to a major Kig-yar colony in orbit over a gas giant in the same system as Expansive Judgement, the capital world of the Blood Covenant - while Expansive Judgement itself was a high-priority target itself, it was also defended by hundreds of warships, making a frontal assault on it impractical and potentially fatal. Instead, Operation: CORSAIR revealed that there was a vital weak point able to be exploited - the Gargarensis gas refinery near the Kig-yar colonies was a vital resource, allowing the Blood Covenant to produce weapons- and fuel-grade plasma, maintaining their fleet. Without it, it would only be a matter of time before the Blood Covenant became inoperational, leaving the planet vulnerable. Though Indigo Team would be forced to stay on the colony until a retrieval force could be deployed, it would lead to Operation: LAMENTATION, the most important battle in the UNSC and Sangheili's campaign against the Blood Covenant.

Sangheili reprisal (2561-2562)

For the most part, however, the Kig-Yar Privateer Alliance went ignored by the major factions, largely because they leased their services out to all involved sides. Even the Sangheili contracted a number of Kig-yar mercenaries, mostly as privateers against Blood Covenant and New Covenant merchant shipping. As the war drew on, though, and the Blood Covenant grew increasingly desperate, they contracted a large number of Kig-Yar Privateer Alliance personnel. Though conventional payment was out of the question, the Jiralhanae offered them a perfect site for the type of colony they preferred, and an ideal piracy base of operations - the asteroid field surrounding Goromakton, a gas giant in the same system as Expansive Judgement. In exchange, the Kig-Yar provided their ships and mercenary warriors to supplement the Blood Covenant's wounded military, and protected the Gargarensis gas refinery facility.

Operation: LAMENTATION changed that situation dramatically. With the destruction of the colonies and the facility, the Blood Covenant-contracted Kig-Yar were left without a base to operate from, unable to dock and resupply. Believing it to be an easy and overlooked target, these privateers launched an assault on a Sangheili colony, Triumphant Declaration, hoping that its plunder would be able to cover the costs neccessary to reestablish themselves. What they hadn't counted on was the Sangheili's swift and overwhelming response - three hundred warships entered the system, utterly obliterating the Kig-yar fleet before it could escape, and launching ground forces to retake the planets population centres.

Seeing the attack on Triumphant Declaration as a declaration of war, the Sangheili Armed Forces mobilised to devastate the infrastructure of the Kig-Yar Privateer Alliance, destroying as many Kig-yar colonies as they found, spreading the message that the Sangheili's genocidal fury had been unleashed upon them. By the end of the campaign, even the Kig-yar themselves were hunting down Privateers, hoping that this act would be percieved as a gesture of goodwill by the Sangheili, and that it would halt their purges. When the War of Vengeance was officially concluded, the Privateer Alliance had long ago ceased to function as a coherent collective, reduced to small bands of disparate criminals isolated even from Kig-yar society.

Though the War of Vengeance saw little disagreement between the UNSC and the SAF, the extermination of the Privateer Alliance was a point of contention among human and Sangheili diplomats. For one thing, the UNSC had invested a considerable amount of time and resources building up a spy network within the Privateer Alliance, hoping that Kig-yar contacts would be able to provide the UNSC with an advantage against the increasingly-powerful New Covenant - a spy network that was now being wiped out by the Sangheili. Though it had little effect on the Human-Sangheili Alliance, the UNSC did not participate in the campaign, and records indicate that at least a few Kig-yar informants were actually covertly evacuated before they could be killed by the Sangheili, in order to recover their valuable knowledge. After the War of Vengeance, the Sangheili would demand these the UNSC hand over these Kig-yar as criminals for execution - records of their existence were purged, and a mass escape from a UNSC "detention" facility saw their escape and disappearance back into Kig-yar space. The Sangheili have vociferously claimed that the UNSC allowed the Kig-yar to escape in order to re-establish their Kig-yar spy network, which the UNSC have denied multiple times.

As the Covenant literally fell apart, rival factions turning against each other, the Unggoy of Balaho found themselves far from the most pressing of their concerns. With the New Covenant, Blood Covenant and Sangheili Armed Forces too busy trying to wipe each other out, the Unggoy rose up, declaring the foundation of the Unggoy Star Empire, the first interstellar Unggoy government in history, making and consolidating swift gains. Methane-rich worlds near Balaho had long been denied to them by the Ministry of Concert for fear their population would spiral out of control, overwhelming the Covenant and leading to another Unggoy Rebellion. These were immediately claimed by the Star Empire - with little else of interest, none of the other factions bothered to contest it. Capturing more than twenty warships from the Oldaraman Shipyards, and buying or recommissioning others, the Imperial Unggoy Navy numbered less than a hundred ships, but it was enough to get their colonisation effort under way, and by 2561 a sizeable portion of the Unggoy population was in the process of colonising their new worlds, and making the prospect of invading and conquering their worlds a more troublesome business than it was worth.

Unfortunately for them, neither the New Covenant nor the Sangheili were eager to see a species that can reproduce so rapidly establish itself as a major force in the Orion Arm, and were equally uneager to go up against their vastly superior numbers. Separate strikes on several fleets and shipyards crippled their naval contingents, isolating the colonies. Lacking the capacity for shipbuilding themselves, the Unggoy were stranded on their colonies - with their rapid breeding, and without the harsh climate of Balaho to offset it, they would soon overburden the planets with their population. A few Unggoy hopefully bartered what they could in exchange for small ships, attempting to reestablish the colonisation effort, but for the most part the Unggoy remained trapped in their own empire. Breeding programs, attempting to control their growth, have largely proven a failure, and within a few generations the Unggoy would have reached a critical point.

Recognising the Unggoy's plight, and feeling that they had a moral obligation to provide aid, UNSC peacekeeping forces moved in swiftly, as much to protect the Unggoy's resource infrastructure as their existence. Unwilling to subjugate the Unggoy again, and just as unwilling to use what they percieved as ineffective warriors in their military, the Sangheili agreed to economic and diplomatic ties with the Unggoy Star Empire. In return for cheap labour, and the creation of Unggoy construction yards, the UNSC would provide the Unggoy access to their interstellar commercial shipping - limiting and controlling their spread through the UEG Foreign and Colony Office. The Unggoy in turn benefitted from UNSC medical advances, including gene therapy to reduce their breeding rate. Not all Unggoy agreed to this, however, and broke away into a number of smaller secessionist factions, thus beginning the Balaho Civil War.

The six-month planetwide conflict would have been considerably longer had it not been for the UNSC's intervention on the side of the Human-friendly Modernists. Thousands of loyal, pro-UNSC Unggoy were trained and equipped with the latest Human weapons and, to the surprise of the UNSC soldiers, who had always perceived the Unggoy as cowards, proved to be extraordinarily competent and tenacious fighters. In contrast, the so-called "Traditionalists" barely worked together at all, and after a few months of hard fighting, Traditionalist soldiers were surrendering to the Modernists in droves. The war was quickly ended with a massive assault by UNSC Marines on the Traditionalists' main base in the north of Balaho's equatorial region. The end of the civil war saw the election of Ippaw dal Pum, a cousin of the famous Yayap, as the Unggoy Star Empire's first High Mistress, and the solidification of the alliance between the Unggoy and the UNSC, who both recognised the need for allies with the discovery of the New Covenant. With the SAF pre-occupied with hunting down the remnants of the Blood Covenant and Kig-Yar Privateers, they allowed the UNSC to take over the duties of keeping the Unggoy down. Instead, the UNSC allowed the Unggoy to rebuild their armed forces and re-establish the Empire, becoming a major commercial power and emerging military superpower in the process. Though the Sangheili watched this with concern, they allowed their stereotypes to blind them to realities, believing that the Unggoy would be easily crushed should the need arise. In an effort to keep a lid on them, they also placed an embargo on Unggoy goods, stifling a potentially enormous market among the Sangheili. This loss of profit meant that the Unggoy were still in the process of building up their navy when the Second Great War was declared, meaning that they were unable to intervene except with financial support for approximately two years.

Aftermath

The intelligence gathered on the New Covenant during Operation: LAMENTATION convinced Arbiter Thel 'Vadam of the SAF that, while peace would never be declared, at least a state of non-aggression was neccessary between the UNSC/SAF alliance and the New Covenant. Though the alliance assumed that this was only a fraction of its firepower, the New Covenant had actually fielded its entire fleet in a gambit that paid off handsomely. Suitably impressing the Sangheili with their numbers and superior tactics, the well-trained Jiralhanae fleet proved that the New Covenant was a force that the Sangheili did not want to reckon with, at least not yet. Eventually, spy channels cultivated among the Brotherhood of Ruskt would bring the New Covenant, Sangheili Armed Forces, and UNSC to sign the Unmoving Virtue Non-Aggression Pact - signed over the site of the first strike against the Blood Covenant, the treaty assured all involved parties that the New Covenant would remain non-aggressive and neutral in Sangheili or UNSC operations, and vice versa.

The loss of Expansive Judgement would be the final nail in the Blood Covenant's coffin. With their last major centre of government destroyed, the smaller remaining colonies would split off, declaring their independence and declaring war upon each other. A number of them would willing accept incorporation into the New Covenant - others were more stubborn, and only the prospect of orbital plasma bombardment brought them to their knees. The loss of Expansive Judgement effectively destroyed the Blood Covenant - what was left were warring Jiralhanae tribes, easily conquered by the New Covenant. The New Covenant benefited significantly from this - in addition to the additional worlds, population and resources now under its control, it had showcased its firepower to the Sangheili.

On the other hand, the New Covenant's victory at Expansive Judgement was a crippling blow for Pierre Plantard's government. Incensed that they had been denied the final, killing blow to the Blood Covenant, and this had actually led to a temporary peace with a species that had declared humanity a heretical race, the furious human population would force Plantard's Conservative Party out of office in the 2562 general election in favour of Jerome Smithson of the Liberal Party, who's first action was a massive military budget cut, diverting the funds to recolonisation and reconstruction efforts, despite ONI's dire warnings of potential threats emerging among the Covenant remnant factions. Initially, this was a popular and indeed neccessary move - the loss of Reach and devastation of Earth left the UNSC in a precarious position, on the verge of economic collapse and heavily dependent on the few remaining colonies for its survival. Over time, however, Smithson's policies would become increasing far-left, questioned even by members of his own party, to the detriment of humanity's attempt at restoring itself - he significantly expanded oversight of surviving colonial territories, an extremely unpopular move by any standards, one that echoed the discontent of the much earlier Insurrectionists against the Colonial Authority, and also expanded government control over assets that had traditionally been the purview of the private sector. Some, such as health care, would improve with the removal of financially bloated and uncaring corporations from the equation, and one of Smithson's first priorities was curtailing the dramatic inflation in influence and abuses of power of the Office of Naval Intelligence, returning it to its status as a mere naval intelligence agency, but most, such as the extensive economic oversight and regulation put in place, would leave the UNSC economically stunted. The reduction of the UNSCDF's military capabilities, leaving it stretched across human frontier space, also left Humanity particularly vulnerable, no matter how much confidence officials expressed at the adherence to treaties signed, and would prove nearly fatal when the Second Great War broke out in 2565.

The destruction of the Kig-Yar Privateer Alliance and the subsequent assimilation of its resources by the UNSC, SAF and New Covenant resulted in a short period of stability among the spacelanes, due to the nearly-complete absence of pirates. This was one of the justifications of the Liberal Party's build-down of the UNSCDF. Even with the SAF and New Covenant's heavily punitive measures against the Kig-Yar, however, some piracy had returned to plague the trade routes by 2565.

The creation of the Unggoy Star Empire saw the beginnings of a power that within ten years would rise to challenge the UNSC, SAF, and even the New Covenant for supremacy in the Orion Arm. Recognising that certain factions within the New Covenant would want to reclaim their former slave workforce, the Unggoy rapidly built up their Armed Forces, supported by grants and trade from the UNSC (Smithson's government could not see what the Unggoy were worried about, convinced of the sanctity the Unmoving Virute Non-Agression Pact, and only desired to open up a new trading market in the USE). With a large, ever-expanding population that was willing to work, the Empire rapidly became a significant economic power, opening up trading alliance with the UNSC and the Prophet of Objection's regime in the New Covenant (this was cut off after the coup by the Governors of Contrition) Due to the SAF embargo on Unggoy goods, however, the Unggoy were denied the trade that would have given them the funds to build up their fleet to wartime levels before the outbreak of the Second Great War, and for two years were only able to provide financial support.

Despite the optimism that had existed with the end of nearly forty years of Human-Covenant conflict, the threat of war was far from distant: Many factions within the New Covenant, especially the Governors of Contrition, were resentful of the Prophet of Objection's "inaction" that had allowed the UNSC and SAF to rise to position of challenging to New Covenant militarily, and wished to finish the xenocide they had started against Humanity. In early 2565, Objection was assassinated by the Governors on the steps of the Council Chamber, and in the resulting confusion that came to be known as the Great Upheaval, the Sangheili-dominated Governors launched a coup, taking over the New Covenant and oppressing the "lower" Kig-Yar and Jiralhanae. Their first foreign policy was to launch a new offensive against the UNSC, beginning the Second Great War.

Timeline

Operation: MACARTHUR, a planet-hopping campaign by the UNSC and SAF, is begun. Stealth Frigates and Prowlers cripple Blood Covenant shipping, while battlegroups strike hard and fast at vital and vulnerable targets.

2557

The Blood Covenant hires privateers and mercenaries from the Kig-Yar Privateer Alliance to prey on UNSC and Sangheili shipping. Megiddo is the victim of countless pirate raids, prompting an expanded ONI presence in the system.

With UNSC and Sangheili battlegroups wiping out strategic assets, including refineries and shipping points, Blood Covenant colonies begin to starve and wither. The Blood Covenant pulls back to Expansive Judgement.

The Interminable Reprisal Campaign begins, with the Sangheili wiping out the Kig-Yar Privateer Alliance, and leaving the Kig-yar as a species with little in the way of infrastructure. For a long time, they will be forced to rely on Sangheili aid, and are once again denied slipspace-capable ships.

Balaho Civil War - The six-month conflict ends with the UNSC-backed Modernists victorious over the Traditionalists.

The Blood Covenant Civil War begins and ends swiftly, as rival Jiralhanae tribes struggle against each other. The few that refuse assimilation when the New Covenant conquer their colonies are wiped out by orbital bombardment. The Blood Covenant is officially declared nonexistent, its last worlds annexed by the New Covenant.

The Unmoving Virtue Treaty is signed between New Covenant, Sangheili and UNSC delegates, officially bringing the War of Vengeance to a close. Smaller tensions and conflicts would continue to be fought, but are excluded from this timeframe.

Participants

UNSC

As humanity began to rebuild and recover from the devastation of the Human-Covenant War, most of the top leadership were reluctant to return to combat operations, fearing a second invasion of Earth, and the beginning of another campaign of genocide against them by one of the more powerful Covenant Remnant factions. However, as more and more technologies entered service rendering not only their own equipment obsolete but also that of the Covenant, the UNSC began to feel more confident. While the Battle of Unmoving Virtue was the first military operation the UNSC had engaged in since the last war, it would not be the last - the skirmishes with the Kig-Yar Privateer Alliance, the attacks on Ulysses and Mandorla, and the battles of Resolute Spirit, Y'Deio, and Renewed Vigour were all fought by humans in defence of human interests. Unmoving Virtue would be the largest cooperative campaign between the two factions, but it would not be the last.

Sangheili Armed Forces

As the Schism drew to a close, the Sangheili found themselves scattered across former Covenant space, with a smaller fleet and suddenly faced with a much larger enemy. That alone nearly threatened the Sangheili with fragmentation into various smaller emppires and thralldoms, but the shattering of their belief in the Great Journey was almost as damaging. The Sangheili Armed Forces took the disparate Sangheili, uniting them with a common goal - vengeance. It is their crusade against the former Covenant factions that lends its name to the War of Vengeance. Like the UNSC, the Sangheili also found itself benefitting from improvements on their weapons and other systems - though humanity was loathe to give up any advantage it possessed, the native ingenuity of Sangheili researchers was finally lifted from the restraints set by the Prophets on non-interference in Forerunner-derived technologies. As they swept through the stars, one by one the enemies of the Sangheili fell - the Blood Covenant was shattered at Unmoving Virtue, the Brotherhood of Ruskt was reduced to a single world, and even the New Covenant, rivalling the Sangheili themselves in terms of strength and territory, lost significant territories before the Unmoving Virtue Treaty.

New Covenant

The first, and to date largest, non-Sangheili group to emerge from the chaotic period as the Covenant collapsed, the New Covenant would form itself around a new trio of Prophet Hierarchs. Seeking to try and keep the Covenant as unified as possible, the Prophets of Objection, Protestation and Devotion made many changes in the internal structuring and organisation of their faction, seeking to make better use of each of their member-races' talents. Yanme'e were elevated to the Warrior Caste, with Huragok taking their former technical roles, while Unggoy were removed from the military totally, relegated to civilian roles to build up the New Covenant infrastructure and to deny them the resources for revolt.

While outwardly the New Covenant claims to follow the religious motivation of the past set of Hierarchs, internally many acknowledge that a holy war simply isn't feasible at the moment. The Treaty of Unmoving Virtue was signed between San'Shyuum, Sangheili and Human dignitaries in 2554, bringing an end to outward hostilities between the New Covenant and the UNSC-Sangheili alliance. This doesn't mean that peace has been declared, and there was no formal end to the war agreed between the parties, but the New Covenant and the allies agreed to a set boundary of territory that neither would cross, in exchange for which the Sangheili leaders agreed to deal with the less built-up "Covenant" groups instead, to ensure security.

Blood Covenant

Though the New Covenant was ruled by three new Prophet Hierarchs, the Blood Covenant rejected this system entirely, and is more accurately described as "Covenant" in name only. Rather, it was lead by a single Jiralhanae warlord, Alpha Chieftain Hephaestus, ruling over thirteen former Covenant colonies, at first based out on Glorious Ascension, a former Sangheili colony, and then jumping from there to Unmoving Virtue, Pious Ascension, and finally Expanisve Judgement. While the Blood Covenant held much less territory than the New Covenant, less than 47%, when the Covenant broke apart Hephaestus managed to bring together a significant number of ships and warriors under his sway, and they maintained the largest military threat to the Sangheili, against whom all the Jiralhanae in the Blood Covenant had sworn eternal undying vengeance against for the murder of former Alpha Chieftain Tartarus at the hands of the Arbiter.

Though the Blood Covenant incorporated many of the races that once made up the Covenant, they held the distinction of including no Prophets. Though the Jiralhanae remained outwardly pious and reverent to former San'Shyuum temples, there was a general undercurrent of belief that the ill tidings of the Jiralhanae in recent times - their devastation by the Sangheili fleet at Delta Halo, the humans at Earth, and against both at the Ark - are a direct result of Prophet meddling. Such "heresy" particularly inflamed the representatives of the New Covenant, especially after the San'Shyuum Ministers of Malediction and Requisition were sent back brutally slaughtered by the Jiralhanae, resulting in the general declaration of hostilities against each other, a foolish move on the part of the Blood Covenant, as soon after this they found themselves facing a two-front war with the UNSC and Sagheili on one side and the New Covenant on the other. Hephaestus was killed at the Battle of Unmoving Virtue, and they lost several significant colonies in the early months of the war to the UNSC/SAF alliance. The Blood Covenant was declared non-existent under the Unmoving Virtue Treaty of 2562 and its territories were absorbed by the New Covenant.

Kig-yar Privateer Alliance

Formed after the fragmentation of the Covenant, the Kig-Yar Privateer Alliance is a major organisation encompassing thirteen star systems and dozens of planets, planetoids and asteroid colonies. A loose collection of pirates, privateers and mercanaries, the Privateer Alliance managed to establish itself as a significant presence during the War of Vengeance, and while its allegiance was constantly shifting depending on who could provide it with better incentive to fight for their cause, they were eventually annihilated by the Sangheili Armed Forces in retaliation after rogue Privateer Alliance ships attacked the relatively minor colony world of Triumphant Declaration.

Seeing the attack on Triumphant Declaration as a declaration of war, the Sangheili Armed Forces mobilised to devastate the infrastructure of the Kig-Yar Privateer Alliance, destroying as many Kig-yar colonies as they found, spreading the message that the Sangheili's genocidal fury had been unleashed upon them. By the end of the campaign, even the Kig-yar themselves were hunting down Privateers, hoping that this act would be percieved as a gesture of goodwill by the Sangheili, and that it would halt their purges. When the War of Vengeance was officially concluded, the Privateer Alliance had long ago ceased to function as a coherent collective, reduced to small bands of disparate criminals isolated even from Kig-yar society.

Though the War of Vengeance saw little disagreement between the UNSC and the SAF, the extermination of the Privateer Alliance was a point of contention among human and Sangheili diplomats. For one thing, the UNSC had invested a considerable amount of time and resources building up a spy network within the Privateer Alliance, hoping that Kig-yar contacts would be able to provide the UNSC with an advantage against the increasingly-powerful New Covenant - a spy network that was now being wiped out by the Sangheili. Though it had little effect on the Human-Sangheili Alliance, the UNSC did not participate in the campaign, and records indicate that at least a few Kig-yar informants were actually covertly evacuated before they could be killed by the Sangheili, in order to recover their valuable knowledge. After the War of Vengeance, the Sangheili would demand these the UNSC hand over these Kig-yar as criminals for execution - records of their existence were purged, and a mass escape from a UNSC "detention" facility saw their escape and disappearance back into Kig-yar space. The Sangheili have vociferously claimed that the UNSC allowed the Kig-yar to escape in order to re-establish their Kig-yar spy network, which the UNSC have denied multiple times.

Unggoy Star Empire

The Unggoy Star Empire was an explosion of Unggoy culture, technology, and territory that immediately followed the collapse of the Covenant, and very nearly ended as soon as it began. As the Jiralhanae and Sangheili engaged in a bitter struggle for supremacy, the Unggoy managed were largely left to their own devices. A small number of ships docket at the Balaho Shipyards were captured by Unggoy workers with little in the way of a struggle, and by 2555 the Unggoy were using these warships to escort massive passenger liners and freighters, captured or stolen, to transport thousands of their people offworld. Long confined to Balaho or small orbital colonies to keep their numbers down, they finally saw their chance to set up an empire of their own. Spreading to the seven nearest star systems, the Unggoy declared their independence and neutrality in the conflict, hoping that their ill-gotten gains would be ignored.

Unfortunately, neither the Sangheili nor the Jiralhanae were eager to see the spread of the Unggoy, especially since both thought the other might recruit large numbers of conscripts for their own militaries. In separate strikes, the Sangheili and Jiralhanae crippled the fledgling Imperial Unggoy Navy badly, with movements against the colonies. Unwilling to waste time and resources glassing the planets, the Sangheili were content to destroy any space travel infrastructure - space docks, ships, orbital gravity elevators, and so on. The Jiralhanae were not so minimalist, and wasted much time attempting to conquer colonies before finally realising that there were other fronts where their troops were better needed. Content with cutting the Unggoy colonies off, both the Sangheili and Jiralhanae shifted their focus back to battling each other.

The colonies themselves would keep in contact, but without space travel, further colonisation was impossible. The colonies of Atatna and Panga would rise to become havens of Unggoy learning and knowledge, becoming colonies to rival the Unggoy homeworld itself - though considering their rather more temperate climates, and the harshness of Balaho's own ecosystem, that wasn't hard. The Star Empire would be largely left alone until the end War of Vengeance, though by 2562 population pressures, combined with the traditional Unggoy reluctance towards birth control and population management, was beginning to put pressure on the colonies for expansion. A few Unggoy hopefully bartered what they could in exchange for small ships, attempting to reestablish the colonisation effort, but for the most part the Unggoy remained trapped in their own empire. Breeding programs, attempting to control their growth, have largely proven a failure, and within a few generations the Unggoy would have reached a critical point.

Recognising the Unggoy's plight, and feeling that they had a moral obligation to provide aid, UNSC peacekeeping forces moved in swiftly, as much to protect the Unggoy's resource infrastructure as their existence. Unwilling to subjugate the Unggoy again, and just as unwilling to use what they percieved as ineffective warriors in their military, the Sangheili agreed to economic and diplomatic ties with the Unggoy Star Empire. In return for cheap labour, and the creation of Unggoy construction yards, the UNSC would provide the Unggoy access to their interstellar commercial shipping - limiting and controlling their spread through the UNSC Department of Colonial Affairs. The Unggoy in turn benefitted from UNSC medical advances, including gene therapy to reduce their breeding rate. Not all Unggoy agreed to this, however, and broke away into a number of smaller secessionist factions, thus beginning the Balaho Civil War.

Brotherhood of Ruskt

Technically, the Brotherhood of Rukt are an offshoot of the Covenant religion, modified by the Brutes for their purposes. After the Schism, and the collapse of the Old Covenant, the Brotherhood of Rukt came to control thirteen colonies, significant enough to hold its own against rival factions, and build up its infrastructure, but too trivial for the Sangheili to bother with. As it built itself up, it waged a war of conquest against other groups, wresting control of isolated planets and star systems from would-be warlords and pirates, eventually holding two dozen colonies under its sway. Its relationship with the Blood Covenant is an odd one - while they admire the sheer power of Hephaestus' faction, and the fact that it is ruled by Jiralhanae rather than Prophets, they refuse to bow down to what they see as an honourless barbarian.

The Brotherhood are particularly notable for their peace treaty with the Sangheili, the only group of Jiralhanae to seek it. The exact circumstances of the treaty are unknown, and both the Sangheili and the Brotherhood refuse to talk about, but a limited exchange of information, technology, goods, and personnel has allowed both groups to secure their borders. The Brotherhood does not seem particularly eager to return to their jihad against the Sangheili and UNSC, but rather played each side during the War of Vengeance by acting as an intelligence organisation for both the alliance and the Blood Covenant.

Quotes

"The Sangheili have fallen from the path they helped to forge for centuries, but no matter. They shall come around, in time. Remember warriors, it was not the Prophets who struck the first blow - the Sangheili were the ones who failed us, not the other way around. The magnitude of their...errors shall be impressed upon them."

"It's hard to say whether it's not just an extension of the Human-Covenant War. On the one hand, it still has many of the same players - the various Covenant Remnant factions, the Sangheili, and the UNSC. On the other hand, we're not on the losing side."

"A Sangheili has trouble remembering that other species have concepts of honour and valour, however alien they are to us. Before we made peace with the humans, the closest we had to ourselves was the Lekgolo. But as the humans burned a path through their enemies with their righteous fury, avenging the restless spirits of the dead, I learned the true measure of honour - and that I had a lot of catching up to do to atone for my past heresy."

"Hell, nobody liked fighting alongside the species that had willingly wiped us out us for nearly thirty years. But they were the only ally available to us - Earth our only stronghold, less than a dozen colonies left, and a shattered military and economic infrastructure left us desperate. And as we worked together, people looked at them as a powerful ally rather than something that could turn on us whenever it wanted. Thankfully, we're no longer in such a vulnerable position."

Bibliography

Michaels, J. R., Official History of the UNSC Army (Naniwa: Luna Publishers, 2563)

Michaels, J. R., Official History of the UNSC Air Force (Naniwa: Luna Publishers, 2564)

Michaels, J. R., Official History of the UNSC Navy (Naniwa: Luna Publishers, 2566)